Providing heart rate monitoring (HRM) and electrocardiogram (ECG) capabilities for wearable products, the Si117x biometric sensor modules are suitable for smart watches and wrist-based, patch-type and other wearables requiring long battery life and enhanced HRM accuracy. To simplify development and speed time to market, Silicon Labs offers a complete, end-to-end sensing solution featuring the Si117x sensor module, HRM algorithm, Wireless Gecko SoCs for Bluetooth® connectivity, and an easy-to-use, wrist-based development kit with sample code and example projects.
Addressing the market need for power efficiency, the Si117x sensors consume less than 50 µA (sensor and LED combined) while performing continuous HRM. A built-in buffer and accelerometer synchronization capabilities save even more system-level power. The sensors’ industry-leading power efficiency enables developers to use smaller batteries in wearable designs without significantly impacting the device’s battery life during continuous monitoring.
The Si117x sensors provide enhanced HRM accuracy for a better end-user experience. The sensors offer fast sampling speeds, a high signal-to-noise ratio (SNR >100 dB), and the ability to cancel out ambient noise and erroneous data, resulting in high-quality signals that make it easier to track heart rates despite challenging physiologies, varying skin tones and the presence of tattoos. A more accurate view of the HR waveform enables biometrics beyond traditional HRM, including heart rate variability (HRV), stress analysis and pulse volume.
The Si117x module’s high level of integration simplifies wearable design and makes it easier to synchronize multiple sensor measurements without adding significant system cost or board area. Each module supports up to four distinct LEDs (all of which can be driven simultaneously), and its four LED drivers are independently programmable (from 1.7 to 310 mA). Additional built-in features include a photodetector, 24-bit ADC with >100 dB dynamic range, I2C and SPI digital interfaces, programmable event interrupt engine, synchronization engine, host communications processor and inputs for two external photodiodes.
The Si117x sensors support Silicon Labs’ proprietary, motion-compensated HRM algorithm optimized for wrist-based sensing and to run on EFM32 Gecko MCUs and EFR32 Wireless Gecko SoCs supporting Bluetooth Low Energy (LE). This unparalleled integration enables system-level power and performance optimization and reduces time to market for developers seeking to add HRM capabilities to their wearable designs.
Pricing and Availability
Samples and volume quantities of the Si117x sensors are available in a 3.7 mm x 7 mm 28-pin LGA module. Silicon Labs also offers Si118x optical biometric sensors with an integrated photodiode in a clear 3 mm x 3 mm QFN package. The company provides a variety of wrist-based ECG and PPG development kits, a Bluetooth-enabled HRM evaluation watch, and an Android-based Triple Heart Application that captures data from multiple devices. For more details and specs, visit Silicon Labs.